Artificial hand-hook type



Feb. 4, 1947. c, MQLLENHOUR 2,415,145

ARTI ICIAL HAND HOOK TYPE Filed Jan. 4, 1945 5 Sheets-Sheet 1 1795- D. c. MOLLENHOUR ARTIFICIAL HAND HOOK. TYPE Filed Jan. 4, 1945 3 Sheets-Sheet 2 I). Munch hour ARTIFICIAL HAND. HOOK TYPE Filed Jan. 4, 1945 3 Sheets-Sheet 3 yum Patented F ab. 4, 1947 ARTIFICIAL HAN D-HOOK TYPE Delbert Clark Mollenhour, Mentone, Ind., as-

signor to Franklin I. Saemann, New York, N. Y.

Application January 4, 1945, Serial No. 571,327

Claims.

This invention relates to artificial hands and has special reference to that type of artificial hand wherein the normal fingers and thumb are replaced by a pair of pivotally connected members acting as gripping tongs.

Certain devices, such as the patent of F. C. Henning 1,365,692 of January 18, 1921, somewhat resemble the present device but it will be noted that in this patent it is necessary to screw up a thumb nut to make the required settin of the gripping tongs and this is a difierent and inefficient way of operating.

Other inventions of this sort have been heretofore used and it is common to provide in these some sort of pawl and ratchet device for holding the members from opening after they have been adjusted to grip an object. In prior inventions of this character once the article had been gripped it has been necessary to release the pawl and ratchet to such an extent that the device moves to full open position before it can grip another object. even though that object may be smaller than the one first gripped.

One important object of the invention is to provide a friction type lock so as to enable the wearer to grip an object in the jaws without using the opposite hand. Obviously this is a great improvement over the use of a thumb screw where it is positively necessary to use the opposite hand and wherein, in order to get a sufficiently tight grip and prevent slipping, one is apt to strip the threads of the screw.

A second important object of the invention is to provide a device of this character wherein an object may be gripped, the device opened just enough to release that object and then close down on a second and smaller object. All of this being accomplished without any full opening of the jaw of the device.

Also in devices of this character it has been common to provide pawl and ratchet means for preventing the device from opening, such pawl and ratchet means being arranged to hold the jaw at certain definite spaced distances. For instance the pawl may engage in a series of notches.

A third important object of the invention is to provide a device of this character wherein the pawl and ratchet means is such as to enable the jaws to be held in spaced relation against opening at an infinity of positions between the fully closed and fully opened positions of these jaws.

A fourth important object of the invention is to provide novel means for adjusting the hand bodily in relation to its connection with the arm,

the device thus providing an artificial wrist movement.

The fifth important object of the invention is to provide a device of this character of extreme simplicity and having but few working parts and those of a construction not liable to such wear or damage as will make the device inefficient in operation.

With the above and other objects in view the invention consists in general of certain novel details of construction and combinations of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly claimed.

In the accompanying drawings, like characters of reference indicate like parts in the several views and Fig. 1 is a side elevation showing one form of the invention.

Fig. 2 is a view partly in elevation and partly in section similar to Fig. 1 but with one of the side members hereinafter described removed.

Fig. 3 is a top plan view of this form of the invention.

Fig. 4 is a rear end view of this 'form of the invention.

Fig. 5 is a section on the line 5- 5 of Fig. 3.

Fig. 6 is a section on the line 6--B of Fig. 2.

Fig. 7 is a section on the line 1-1 of Fig. 1.

Fig. 8 is an enlarged fragmentary elevation showing the pawl in released position.

Fig. 9 is a view similar to Fig. 8 but with one of the side plates removed.

Fig. 10 is a side elevation of a modified form of the invention.

Fig. 11 is a fragmentary elevation from the front or nose end of the invention in its modified form.

Fig. 12 is a rear elevation of this modified form.

Fig. 13 is a face view of one of the jaws in the modified form.

Fig. 14 is a face view of the other of said jaws.

In the construction of the invention as shown in Figs. 1 to 9 there is provided a pair of members indicated in general at It and I I. The member l0 consists of a pair of spaced side plates [2 having general conformation when viewed laterally of the partially flexed fingers and body of a human hand. These members are held in spaced relation by spacers l 3 which may be suitably held in position as by welding, rivet or the like. Also, toward the ends of the fingers there is provided a space stop l4 which, as will be presently understood, acts as a stop and gripping jaw. The other member Il fits between the plates 12 and has a curved body 15 with straight ends I6. This member II is pivoted to the plates It by a pivot Ii and the plates I2 each has an arcuate surface I8 concentric to the pivot I'I. Adjacent the rear of the member I I there is provided an opening I9 which straddles the surface It and has an outer side as at 9- Th s Outer side is so inclined that it is closer to the surface I8 at its rear end than at its forward end and between the side 2d and the two surfaces It is held a pin 2i constituting a frictional pawl in its relation to the surface I8. This pawl operates in such manner that as the member II tends to move in the direction of the arrow the end of the side 26 which is closer to the surfaces I8 will engage the pawl and jam it against the surfaces I8 thus locking the member II from such movement. However, if the pin 2I is moved toward the opposite side of the opening I9 then the space between the side ZII and the surfaces It will be such that the pin will no longer be gripped as the member II can swing freely to its extreme position of opening.

In order to effect release movement of the pin 2| there is provided a lever '22 U-shaped in cross section and straddling the rear end It of the member II. This lever is pivoted to the member II at 2 3 and is provided with a notch 24 in each of its sides, these notches engaging the pin 2!. The lever 22 is normally biassed by a compression spring 25 located between the upper end portions of the member II and the lever 22. This spring normally biasses the lever 22 in such manner that the pin 2i is urged toward what may be termed the narrower end of the opening I9. However, if the lever 22 be pressed, by the fingers or otherwise, against the action of the spring 25 the pin 2i will be urged toward the wider end of the opening III. Thus the lever 22 normally holds the pin in latching position but may be moved to release the pin. On the extremity of the member II is a small lug 25 and pivotally connected to the lever 22 is a latching loop 2'1 which normally is positioned as shown in Fig. 1 but which, upon the compression of the spring 25, may be swung to the position shown in Fig 8 thus holding the pin 2I constantly in disengaged position. An opening 28 is provided adjacent the lug 26 for the connection of the wire or cord leading to the usual harness arrangement for devices of this character.

The member I I is connected, rearwardly of the pivot IT, to a pin 29 carried by the plates I2 at the forward part of the device by means of a coiled tension spring to. This spring is connected to the member II at a reduced thickness portion 3I of said member. As will be seen from Fig. 2 the spring 38 tends to urge the member II to swing in the direction of the arrow A, the action of this spring being normally resisted by the pawl 22 I. At the forward end of the member II there is provided a notch 32 which engages with the member I4, this forward end slipping between the plates I2 to effect such engagement. Under these circumstances any object, such as a pencil, placed between the finger tip portions of the plates I2 and resting against member It may be held in such position by movement of the member II in the direction opposite that shown by the arrow A. This movement may be effected by proper movement of the harness or may be manually performed if the user has one hand remaining.

Extending rearwardly from between the plates I2 is a bar 33 which carries on its rear end a screw threaded portion 3:3 by means of which it may be attached to a tlneaded socket such as is commonly used on the forearm of a person whose hand has been amputated. A stop plate 35 is welded or otherwise secured at the forward end of the screw 3t. A U-shaped pin 36 has one long leg 37 which passes through the forward end of the bar 33 and through the plates I2 to act as a pivot on which the plates and member 33 may pivot in relation to a screw 3%. Thus U- shaped pin BIB also has a short leg 58. The plates I2 are provided with a series of holes 39 spaced on a line concentric to the pivot leg 31. Similarly the bar 33 has a hole it. The short leg 38 is adapted to pass through the hole M3 and through selected holes 39 in the plates I2 thus locking the hand portion of the device in wrist adjusted relation to the screw 34. In order to hold the short leg 38 from movement out of registration with the hole IB there is provided on the disc 35 a pair of lugs II between which this leg 38 slides. I

Loops 42 are carried by the plates I2 and may be used in steadying the hand when laid on a surface, in fastening a package or the like thereto and in various other ways, such as holding in straight position objects such as pencils, chisels, etc.

In the form of the invention shown in Figs. 10 to 14 the construction is substantially the same with the exception that a different form of jaw and a different pawl arrangement is used. In this pawl arrangement a lever 53, U-shaped in cross section has its sides straddling the member II as before and these sides are pivoted to said member II by a pivot 44. The end of this lever toward the pivot II engages directly on the surfaces I8, the lever being slightly biassed so that the engaging ends lie forwardly of a line connecting the pivot II and the pivot M. In place of the compression spring 25 there is employed a tension spring 55 which has one end hooked to the forward part of the lever 43 and its other end engagin in one of the coils of the spring 30 as clearly shown in Fig. 10.

At the forward end of the member III the plates I2 have inserted between them a block or spacer Mi which is secured in position by rivets M. This spacer is so positioned as to lie slightly above the lower edges of gripping jaws 48 formed on the under side of the forward ends of the-plates I2. This facing provides a notch' lIl running longitudinally of the device and also a transverse notch 58 is out across the block 46 and the plates I2 as shown clearly in Fig. 13. The member I I has its forward end flattened to provide a width equal to the width between the outer surfaces of the plates I2 and this flattened portion forms a 'j aw ti which has its upper surface provided with suitable corrugations 52 as shown clearly in Fig. 14. In this form of the device the loops 53 are carried by the member I I and this member II is prolonged forwardlyto form a re-bent hook 54 which may be used in carrying heavy weights.

Referring now to Fig. 2 it may be assumed that in the dotted line position there shown an article has been gripped which willrbe held tightly between the member I I and the forward end of the member 'II. When it is desired to release this article it is merely necessary to compress the spring 25 tightly by movement of the lever 22 and to allow the forward end of the member II to move slightly in the direction of the arrow A. The object grasped will be released and upon releasing tension on the spring 25 the member II will be held against further opening. A smaller object may then be placed in position for gripping between the member Id and the forward end of the member ll. Obviously the operation of the form shown in Figs. to 14 will be identical so for as it being unnecessary to open the jaws to their fullest extent for grasping an object.

What is claimed is:

1. In an artificial hand, a pair of pivotally connected members having coacting jaws at their forward ends, spring means urging said jaws apart, and a friction pawl and ratchet device having coacting parts associated with respective members and resisting movement of said members to open said jaws.

2. In an artificial hand, a pair of pivotally connected members having coacting jaws at their forward ends, spring means urging said jaws apart, one of said members having a portion provided with an arcuate surface concentric with the pivotal axis of said members, and a cylindrical gripping member for clamping movement on said arcuate surface by the other member and frictionally traversing said surface, said last member acting against the action of said spring.

3. In an artificial hand, a pair of pivotally connected members having coacting jaws at their forward ends, spring means urging said jaws apart, one of said members having a portion provided with an arcuate surface concentric with the pivotal axis of said members, a cylindrical friction pawl supported for clamping movement on said arcuate surface by the other member and traversing said surface, said pawl acting against the action of said spring, and manually operable means for relieving the pawl from active cooperation with said surface.

4. In an artificial hand, a pair of pivotally connected members having coacting jaws at their forward ends, spring means urging said jaws apart, one of said members having a portion provided with an arcuate surface concentric with the pivotal axis of said members, a cylindrical gripping member for clamping movement on said arcuate surface by theother member and frictionally traversing said surface, said last member acting against the action of said spring, and releasable latch means for holding said gripping member from active contact with said surface.

5. In an artificial hand, a pair of pivotally connected members having coacting jaws at their forward ends, spring means urging said jaws apart, one of said members having a portion provided with an arcuate surface concentric with the pivotal axis of said members, a cylindrical gripping member for clamping movement on said arcuate surface by the other member and frictionally traversing said surface, said last member acting against the action of said spring, manually operable means for relieving the gripping member from active cooperation with said surface, and releasable latch means for holding said pawl from active contact with said surface.

6. In an artificial hand, a pair of pivotally connected members having coacting jaws at their forward ends, spring means urging said jaws apart, a friction pawl and ratchet device having coacting parts associated with respective members and resisting movement of said members to open said jaws, attaching means for securing one of said members to a users arm, a pivot connecting said attaching means to the last mentioned member, said last member having a series of spaced pin holes on a line concentric to the last pivot, said attaching means having a pin hole registerable selectively with said pin holes, a pin engaging the registering pin holes, and means to release said pin from an engaged hole upon pressure of the means against a hard surface.

'7. In an artificial hand, a pair of pivotally connected members having coacting jaws at their forward ends, spring means urging said jaws apart, one of said members having a portion provided with an arcuate surface concentric with the pivotal axis of said members, a cylindrical friction pawl supported for clamping movement on said arcuate surface by the other member and traversing said surface, said pawl acting against the action of said spring, attaching means for securing one of said members to a users arm, a pivot connecting said attaching means to the last mentioned member, said last member having a series of spaced pin holes on a line concentric to the last pivot, said attaching means having a pin hole registerable selectively with said pin holes, a pin engaging the registering pin holes and means to release said pin from an. engaged hole upon pressure of the means against a hard surface.

8. In an artificial hand, a pair of pivotally connected members having coacting jaws at their forward ends, spring means urging said jaws apart, one of said members having a portion provided with an arcuate surface concentric with the pivotal axis of said members, a cylindrical friction pawl supported for clamping movement on said arcuate surface by the other member and traversing said surface, said pawl acting against the action of said spring, manually operable means for relieving the pawl from active cooperation with said surface, attaching means for securing one of said members to a users arm, a pivot connecting said attaching means to the last mentioned member, said last member having a series of spaced pin holes on a line concentric to the last pivot, said attaching means having a pin hole registerable selectively with said pin holes, a pin engaging the registering pin holes and means to release said pin from an engagedhole upon pressure of the means against a hard surface.

9. In an artificial hand, a pair of pivotally connected members having coacting jaws at their forward ends, a spring means urging said jaws apart, one of said members having a portion provided with an arcuate surface concentric with the pivotal axis of said members, a cylindrical friction pawl supported for clamping movement on said arcuate surface by the other member and traversing said surface, said pawl acting against the action of said spring, releasable latch means for holding said pawl from active contact with said surface, attaching means for securing one of said members to a users arm, a pivot connecting said attaching means to the last mentioned member, said last member having a series of spaced pin holes on a line concentric to the last pivot, said attaching means having a pin hole registerable selectively with said pin holes, a pin engaging the registering pin holes.

10. In an artificial hand, a pair of pivotally connected members having coacting jaws at their forward ends, spring means urging said jaws apart, one of said members having a portion provided with an arcuate surface concentric with the pivotal axis of said members, a friction pawl carried by the other member and traversing said surface, said pawl acting against the action of said spring, manually operable means for relieving the pawl from active cooperation with said surface, releasable latch means for holding said pawl from active contact with said surface, at-

REFERENCES CITED The following references are :of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,029,794 Corley June 18,1912 1,284,875 Caron Nov. 12, .1918

Henning J an. 18, 1921 

